Colour-changing windows get a palette upgrade

A new research paper could show how to easily and inexpensively expand the colour palette for glass that changes colour based on voltage. Researchers working on nanophotonics at Rice University have released a new report detailing how the use of the hydrocarbon molecule perylene can create glass able to turn two different colours at low voltage.

“When we put charges on the molecules or remove charges from them, they go from clear to a vivid color,” said Halas, director of the Laboratory for Nanophotonics (LANP), lead scientist on the new study and the director of Rice’s Smalley-Curl Institute.

“We sandwiched these molecules between glass, and we’re able to make something that looks like a window, but the window changes to different types of colour depending on how we apply a very low voltage.”

The new colour-changing glass varies its colouration depending on polarity, meaning that a positive voltage will produce one colour and a negative voltage another. The importance of the Rice team’s new method is that until now, multicolour varieties of such glass have required a much more significant voltage, limiting their use.

The type of glass itself, changing colour as a result of applied voltage, is known as electrochromic  glass and is enjoying growing popularity. The market for such material has been estimated at a value of more than $2.5bn by 2020. Aside from the visual appeal, electrochromic glass is in demand for its light and heat-blocking properties.

Grant Stec and Adam Lauchner of Rice University’s Laboratory for Nanophotonics show off the glass. Images courtesy of Jeff Fitlow/Rice University

In 2013, then-Rice physicist Alejandro Manjavacas found that polycyclic aromatic hydrocarbons (PAHs), the family of molecules that perylene belongs to, with just a few carbon rings should produce visible plasmons. There are dozens of PAHs, all of which contain rings of carbon atoms that are decorated with hydrogen atoms.

Waves of energy that can interact with and harvest energy from passing light depending on their frequency, plasmons are a rhythmic movement in the sea of electrons that constantly flow across the surface of conductive nanoparticles. Building off Manjavacas’ work, the researchers were able to work out that the PAH plasmons were highly sensitive to charge, leading them to the conclusion they could be easily utilised for electrochromic glass.

“Dr Halas learned that one of the major hurdles in the electrochromic device industry was making a window that could be clear in one state and completely black in another,” study co-lead author Grant Stec said. “We set out to do that and found a combination of PAHs that captured no visible light at zero volts and almost all visible light at low voltage.”

The new project took almost two years to complete and relied on Stec’s design of the perylene-containing nonwater-based conductive gel that’s sandwiched between glass layers. In experimenting with the assembled window, the team found that just 4 volts was enough to turn the clear window greenish-yellow, and applying negative 3.5 volts turned it blue.

Later in the project, the team produced a second window capable of going from clear to black. In all their experiments, they found that the colour change takes a few minutes but Halas said that the transition time is improvable with additional engineering.

Footage of fatal crash involving self-driving Uber released

The Tempe Police Department has released the first footage of this week’s fatal crash involving a self-driving Uber. Police had previously said that the Uber, which had a safety driver inside, did not slow down before it struck the victim, something the footage appears to confirm.

Source: The Verge

Police ask Google to help in the pursuit of two gunmen

Google may have helped solve two separate crimes committed roughly one-a-half years apart. According to reports, Raleigh police presented Google with warrants for data from all the mobile devices that were within a certain distance of the respective crime scenes at the time the crimes were committed.

Source: Tech Crunch

Teenager hacks "tamper-proof" cryptocurrency wallet

A hardware wallet designed to store cryptocurrencies, and touted by its manufacturer as tamper-proof, has been hacked by a British 15-year-old. Saleem Rashid said he had written code that gave him a back door into the Ledger Nano S, which would allow a malicious attacker to drain the wallet of funds.

Source: BBC

Tooth-mounted sensor tracks what your're eating

Scientists at Tufts University have developed a wireless sensor that can be attached onto a person’s tooth to track what they are eating and drinking. In their study, the researchers describe how the sensor is able to transmit information about a person’s glucose, salt and alcohol intake.

Source: Alphr

Scientists develop AI software that can reproduce like a living thing

Computer scientists have created a neural network that continually self improves by mimicking the biological self-replication process. “Self-replication is a key aspect of biological life that has been largely overlooked in Artificial Intelligence systems,” the scientists are quoted as saying.

Source: The Register

Boring Company unveils proposed ‘Loop’ route

Elon Musk’s Boring Company has unveiled the first leg of its hyperloop project, which is a ‘Loop’ transit system to travel between Washington D.C. and Baltimore in 15 minutes. The Boring Company’s main project is its network of tunnels under Los Angeles, where it already started digging last year.

Source: Electrek

XPRIZE launches contest to build remote-controlled robot avatars

Prize fund XPRIZE and All Nippon Airways are offering $10 million reward to research teas who develop tech that eliminates the need to physically travel. The initial idea is that instead of plane travel, people could use goggles, ear phones and haptic tech to control a humanoid robot and experience different locations.

Source: Tech Crunch

NASA reveals plans for huge spacecraft to blow up asteroids

NASA has revealed plans for a huge nuclear spacecraft capable of shunting or blowing up an asteroid if it was on course to wipe out life on Earth. The agency published details of its Hammer deterrent, which is an eight tonne spaceship capable of deflecting a giant space rock.

Source: The Telegraph

Sierra Leone hosts the world’s first blockchain-powered elections

Sierra Leone recorded votes in its recent election to a blockchain. The tech, anonymously stored votes in an immutable ledger, thereby offering instant access to the election results. “This is the first time a government election is using blockchain technology,” said Leonardo Gammar of Agora, the company behind the technology.

Source: Quartz

AI-powered robot shoots perfect free throws

Japanese news agency Asahi Shimbun has reported on a AI-powered robot that shoots perfect free throws in a game of basketball. The robot was training by repeating shots, up to 12 feet from the hoop, 200,000 times, and its developers said it can hit these close shots with almost perfect accuracy.

Source: Motherboard

Russia accused of engineering cyberattacks by the US

Russia has been accused of engineering a series of cyberattacks that targeted critical infrastructure in America and Europe, which could have sabotaged or shut down power plants. US officials and private security firms claim the attacks are a signal by Russia that it could disrupt the West’s critical facilities.

Google founder Larry Page unveils self-flying air taxi

A firm funded by Google founder Larry Page has unveiled an electric, self-flying air taxi that can travel at up to 180 km/h (110mph). The taxi takes off and lands vertically, and can do 100 km on a single charge. It will eventually be available to customers as a service "similar to an airline or a rideshare".

Source: BBC